Deicing device



L.. D. BQYCE DEICING DEVICE' Filed Feb. 6, 195o July zo, 1954 Patented July 20, 1954 DEICING DEVICE Leonard D. Boyce, Kirkwood, Mo., assignor to Carter Carburetor Corporation, St. Louis; Mo.,

a corporation 'ofDelaWare Appucaun February e, 195o, serial No. 142,629

This invention relates to carburetors. for inf ternal combustion engines and consists particularly in means for applying heat to those portions of the mixture conduit adjacent the idle port and throttle valve.

As the air fuel mixture in a carburetor passes through the venturis, its pressure and consequently its temperature decrease, and vany m'oisture present condenses and tends to freeze onthe throttle valve and on the mixture conduit Walls adjacent the id le port and throttle; this results in considerable interference with satisfactory operation of the carburetor. The icing condition is further aggravated by the presence of heat insulating device between the carburetor andthe manifold.

Consequently, an object of the invention is to provide means for applying heat to those portions of the mixture conduit adjacent the throttle and idle port. I

A second object is to utilize insofar as possible present passageways in the conventional'carburetor structures for the transmission'of heat to this area.

Another object is to utilize heated air provided to the automatic choke control yfor heating the mixture conduit adjacent the throttle;

A still further object is to utilize manifold suction to draw the heated air from the automatic choke control housing to the Vicinity ofwthe throttle and idle port'. f

Additional objects land advantages of, the invention will appear from a reading of the disclosure in connection with the drawings in' which:

Fig. l is a vertical section through a carburetor incorporating my invention;`

Fig. 2 is a view showing the automatic choke control housing and the'hotair connectionlbetween it and a manifold stove;

Fig. 3 is a plan view of the carburetor insulating spacer;

Fig. 4. is a plan View of lower portion of the mixture conduit wall structure showing the throttle valve and shaft.

Fig. l shows a carburetor formed with an Aair horn 5, and mixture conduit `t. Admission ,of air to the mixture conduit is regulated by unbalanced disk choke valve l', mounted on rotatable shait t, which is journalled in the `walls of air horn 5. A choke control mechanism is mounted on the air horn andcomprises housing 9, cover IG, bimetallic thermostat `I .l for urging the choke valve toward closed position at low temperatures, and Icrank I .2, one end of which abuts against the outerend Aof the,rmestat ,LI the 11 claims. (o1. 12s- 122) 2 other end being secured to choke shaft 8, suction actuated piston Idslidably mounted in cylinder Ida for assisting the choke valve toward open position under certain conditions, and hot air'inlet I6. Athin partition member I5; formed with an arcuate opening I3, to permit movement of crank I2 therethrough, is interposed loetween cover Ill and housing 9.

4Posterior to choke'valve l', in mixture conduit Bfis formed a series of `concentric venturis Il the'outermost comprising part of the mixture conduit wall structure and the inner ones being supported centrally inthe mixture conduit by Awebs I8 and IQ. A float controlled constant level fuel bowl 20 is formed 'adjacent the outer wall of mixture conduit 6, and communicates with mixture conduit 6 through a metering orice (not shown), passageway 2|, and main nozzle 23.

The lower portions of mixture conduit 6 are formed by an' insulating spacer 25 and body flangecasting 2t and are secured to each other and to the upper portion by means of screwsor other suitable means' (not shown), Athrottle Valve v28 is mounted on throttle shaft 29, which `is rotatably' journalled in body ',ilange casting`26. Fuel for idling is provided via 'passageway 3), idle orifice tube 3l; passageway 32, and idle port 33, whichr discharges into mixture conduit 6 `adjacent throttle valve 2.8. A stove 35, having air inlet 36 and air outlet 3l is'mounted on exhaust manifold Se to provide heated air for the operation of thermostat II. Stove outlet 3l is connected to choke'control hot air inlet It by suitable tubular passage- Ways.` Heated air is drawn into the thermostat chamber through inlet I5, past thermostat 'iI, and out through arcuate slot l' Yt'by manifold suction. Manifold suction is communicated to the lower surface of piston it, by lpassageway 39 formed in the carburetor wall 'structure and communicating with mixtureconduit 'at'suction port 46, posterior to throttle 28. `A groove fil is Vformed in the wall of cylinder Ilia adjacent'piston I4 to allow the vacuum in passageway 3e to draw heated air from manifold stove 35 past thermostat Il and into mixture conduit 6.

`In orderto fully utilize the heated air drawn through passageway 39 for preventing icingY adjacent throttle valve 29, that portion d2' of passageway 39 Vadjacent throttle valve shaft 2t is arranged to intersect or be intersected b y throttle shaft 29 and is enlarged to slightly greater diameter than shaft 29, a similar enlarged chamber 43 Iis formedvin casting 2 6 adjacent the other end a of shaft 29, an outlet passageway 44 is formed between the lower end of chamber i3 and mixture conduit 6, and an annular passage 45 is formed in insulating spacer 25 to provide communication between passageway 39 and chamber e3.

During operation of the engine warm air is drawn from manifold stove 35 through inlet i6, past thermostat il, through slot i3, past piston li through groove il and passageways 39 and Q into chambers @l2 and 33, and thence via outlets d and 114 into mixture conduit 6, meanwhile heating the mixture conduit wall structure adjacent the throttle, the throttle valve shaft, and the valve itself, thus preventing icing in the mixture conduit adjacent the throttle and idle port and on the throttle valve.

It is to be understood that while a preferred form of my invention is shown and described in the application, the exclusive use of all rnodifications as come within the scope of the appended claims is contemplated.

I claim:

1. In a carburetor having a mixture conduit and choke and throttle valves therein, a throttle h shaft journalled in the walls of said mixture conduit, a thermostatic choke control device, a source of heated air communicating with said choke control device, a passageway communicating between said choke control device and said mixture conduit posterior to said throttle, said passageway being formed with an enlarged portion adjacent the end of said throttle shaft.

2. In a carburetor having a mixture conduit provided with a choke valve and a throttle valve, a thermostatic choke control device, a shaft for said throttle valve rotatably journalled in the walls of said mixture conduit, a source of heated 4air communicating with said choke control device, a passageway connecting said choke control device and said mixture conduit posterior to said throttle, and an annular passage surrounding said mixture conduit anterior to said throttle and communicating with said passageway.

3. In a carburetor having a mixture conduit provided with a choke valve and a throttle valve,

Aa thermostatic choke control device, a shaft for said throttle valve rotatably journalled in the walls of said mixture conduit, a source of heated air communicating with said choke control device, a passageway connecting said choke control device and said mixture conduit posterior to said throttle, and an annular passage surrounding said mixture conduit anterior to said throttle and communicating with said passageway, said passageway being formed with an enlarged portion intersecting said throttle shaft.

4. In a carburetor having a mixture conduit provided with a choke valve and a throttle valve, a thermostatic choke control device, a shaft for said throttle valve rotatably journalled in the walls of said mixture conduit, a source of heated air communicating with said choke control device, a passageway connecting said choke control device and said mixture conduit posterior to said throttle, an annular passage surrounding said mixture conduit anterior to said throttle and communicating with said passageway, said passageway being formed with an enlarged portion intersecting said throttle shaft, and a similar enlarged portion intersecting the opposite end of said throttle shaft and communicating at its upper end with said annular passage and at its lower end with the mixture conduit.

5. In combination with an internal combustion engine having intake and exhaust manifolds, a

carburetor having a mixture conduit, choke and throttle valves therein, a thermostatic device for controlling said choke valve, a stove, passage means for transmitting heated air from said stove to said thermostatic device, and means for conducting said heated air for circulation in said mixture conduit wall adjacent said throttle..

6. In combination with an internal combustion engine having intake and exhaust manifolds, a carburetor having a mixture conduit, choke and throttle valves therein, shafts for said valves rotatably journalled in the mixture conduit Wall, a thermostatic device for controlling said choke valve, a stove on said exhaust manifold, passage means for transmitting heated air from said stove to said thermostatic device, suction means for conducting said heated air from said thermostatic device for circulation in said mixture conduit wall adjacent said throttle shaft, said suction means comprising a passageway connecting said thermostatic device with said mixture conduit posterior to said throttle, and an annular passage surrounding said mixture conduit anterior to said throttle and communicating with said first named passageway.

7. In combination with an internal combustion engine having intake and exhaust manifolds, a carburetor having a mixture conduit, choke and throttle valves therein, shafts for said valves rotatably journalled in the mixture conduit wall, a thermostatic device for controlling said choke valve, a stove on said exhaust manifold, passage means for transmitting heated air from said stove to said thermostatic device, suction means for conducting said heated air from said thermostatic device for circulation in said mixture conduit wall adjacent said throttle shaft, said suction means comprising a passageway connecting said thermostatic device with said mixture conduit posterior to said throttle, an annular passage surrounding said mixture conduit anterior to said throttle and communicating with said rst named passageway, and enlarged chambers intersecting the ends of said throttle shaft and communicating at their upper ends with said passageway and annular passage, respectively, and at their lower ends with said mixture conduits.

8. In combination with an internal combustion engine, a fuel mixture conduit having a throttle valve therein, an idle passage discharging into said conduit, a source of heated air, laterally extending passage means in heat exchange relation with a substantial portion of the periphery of said mixture conduit and with said idle passage, and means for conducting heated air from said stove to said passage means.

9. In combination with an internal combustion engine, wall structure forming a fuel mixture conduit, a throttle shaft journalled at both ends in said wall structure, a throttle valve mounted on said shaft, passage means in said wall structure having a portion adjacent both ends of said throttle shaft, a source of heated air, and means for conducting heated air from said source to said passage means for preventing the formation of ice in said mixture conduit.

10. In a carburetor having a mixture conduit and choke and throttle valves therein, a throttle shaft journalled in the walls of said mixture conduit, a thermostatic choke control device having a suction motor, a source of heated air communicating with said choke control device, a passageway under control of said suction motor and communicating between said choke control device and for conducting heated fluid, said passageway being intersected by at least one of said journal bearings for heating said throttle shaft and throttle valve to reduce icing tendency.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,188,002 Farr Jan. 23, 1940 2,269,706 Brown Jan. 13, 1942 

